The present invention relates generally to hose fittings and more specifically to a universal hose fittings.
Presently in the railroad industry there are two types of American Association of Railroads (AAR) approved fittings for airbrake hoses to hose couplings. As illustrated in FIG. 1, the first is a crimped ferrule fitting and the second, as illustrated in FIG. 2, a band clamp fitting. The hose coupling 10 of FIG. 1 includes a stem 12 having a hose stop flange 14 and an annular recess 16 at the proximal end of the stem. A reduced diameter portion includes a plurality of radial ridges 18. The hose 20 is inserted onto the stem abutting the hose stop flange 14 with a ferrule 22 thereon and crimped with one end lying in the annular recess 16. The crimping is performed by a special machine depending upon the design of the stem 12.
Although this design operates satisfactorily, it does not allow for replacement of hoses in the field. The crimped ferrule type fitting normally requires a special, highly priced machine to form the necessary crimping. Accordingly, crimped ferrule-type fittings have to be returned to the maintenance shop to have the new hose crimped thereon. In actuality, what happens is that the maintenance people attempt to secure the hose to the stem using a band clamp. Normally, the band clamp is simply too weak to hold the hose in combination with the specific stem structure 12. Ultimately the hose slips off the fitting thereby necessitates replacement of the hose assembly. Thus time is lost not only because of the extended train delays, but by the requirement to send the hose assembly to a maintenance shop which has the specialized highly priced crimping machine.
The band clamp hose fitting coupling 30 of FIG. 2 includes a stem 32 with a hose stop flange 34. A pair of oppositely facing shoulders 36 and 38 are interconnected by a reduced diameter section to form an annular recess 40. The distal end of the stem 32 includes an enlarged bulbous 42. A those 44 is inserted over the stem 32 to come to rest against the hose stop flange 34. A band clamp 46 is placed over the recess 40 and tightened to secure the hose to the stem.